Clematis is not easy to start from seed and may not breed true or be exactly like the parent plant. It is much more practical to grow from cuttings taken from the mother plant and rooted in moist soil. Early summer is a good time to take cuttings. You can also take a long branch and lie it on the ground covering one foot of the clematis stem with damp soil. This will encourage roots to form on the underground stem. In a year you can cut this stem from the mother plant and have a new clematis. Keep growing, Marianne Binetti